What are request headers?
Notes sent with every request
When a browser asks a website for a page, it sends short labelled lines of information along with the request. These are HTTP request headers. They tell the server which site is being asked for and what the browser can handle, so the server can send back a suitable response.
The headers you will see most
Host names the site being requested. User-Agent describes the requesting software, usually a browser and operating system. Accept lists the content types the software can use, Accept-Language lists preferred languages, and Accept-Encoding lists the compression formats it understands. DNT and Sec-GPC are privacy preference signals: they ask sites to limit tracking, but sending one does not guarantee a site will act on it.
Why some headers are not shown
The request headers tool shows a selected set. Headers such as Cookie and Authorization are left out because they can contain private login details. Forwarding headers are left out because they can describe internal infrastructure.
Treat them as claims, not facts
Headers are supplied by the client, and any client can set them to whatever it likes. A proxy, VPN or content delivery network between you and the server can also add or change them. A User-Agent that says it is a particular browser only shows what the software chose to report.
See your request headers · See your IP address · All tools and guides